Microsoft is said to be creating a Halo-themed Cortana app that will offer voice control input on Windows Phone, challenge iPhone’s Siri format, reports claim.

ZDnet reports that back in June, screens of an early Windows Phone OS version were leaked, showing an app called ‘zCortana’. The ‘z’ suggests it was a test build.

The site claims that this is in fact a personal assistant app on Windows Phone featuring Halo’s very own AI guide to all things technical, Cortana. It is believed that the app will launch early 2014 and will replace Microsoft’s current ‘TellMe’ service.

Cortana is said to use Bing learning technology ‘Satori’ to learn and adapt to your persoal habits and offer the best assistance possible.

The article author writes, “Cortana will be more than just an app that lets users interact with their phones more naturally using voice commands. Cortana is core to the makeover of the entire “shell” — the core services and experience — of the future versions of Windows Phone, Windows and the Xbox One operating systems, from what I’ve heard from my contacts.”

Microsoft CEO Steve Ballmer issued a company restructure memo in July, and one possibly connected paragraph reads, “Our UI will be deeply personalized, based on the advanced, almost magical, intelligence in our cloud that learns more and more over time about people and the world. Our shell will natively support all of our essential services, and will be great at responding seamlessly to what people ask for, and even anticipating what they need before they ask for it.”

Is he talking about the Cortana tech here? Let us know what you think below.